Coupling



Jan. 10, 1956 M. P. EsPY ET AL COUPLING Filed April 26, 1952 l mw km am @n WW' @/Nll mv l a: 1 bm c 7 ,w 22. mv Wm WNW CGUPLINGJ.

Melvin P. Espy, Mount Royal, Quebec, Canadayand liant W.Pitman, Colgate, *and* Burnham Josselyn; Kingsville, Md., `assignors to The Glenn L. Martin Company;

Middle River-,H Md.; fa corporation# of AMaryland f Application April 26, `1952,75,trial-No..284,602

3 Claimsf-J (Cl. 2844419) This: inventionrelatesto couplings for highnpressureA hydraulic linesyandmore particularly `to improvementsm nited States Patente' the 4`construction of `such'couplings Vcontaining valves for is veryV desirable to have `a coupling which can be quickly I and easily coupled anduncoupled by hand, which will withstand the high pressures incident to the testing operaf tion without leakage lor failure, :and which willautomatically prevent thel loss of iiuid from thelines while remaining 'uncoupled:

A rnajor-'disadvantageof couplings intended to bel coupled and uncoupledby hand, arises from the' ditiiculty of effectively sealingsuch couplings against leakage, espe ciallyduring high pressure-operation; since the' force which can be Aexerted by handis ordinarily'not sucient to provide anetiective seal at thejunction between the two elements of the coupling.'`

Anr additional disadvantage of couplingswcontaining valves'to prevent Vloss of lluidzwhileuncoupled lies in they fact that the valve mechanism-so restricts'the ow of fluid through Vthe coupling Vthat'for any substantial'ilowrate the pressure drop through the coupling is very high."

Where the number of. couplingsvused vis relatively large, as in a hydraulictest set-up, thecumulativev pressure drop through the iittings is quite troublesomef- Itis ther-object of this invention; therefore, to provide a hydraulic coupling which .mayv be easily," and ,quickly E4 uncoupled 'by hand andy which.. rwill uprevent thezloss-l of fluid` from -thejhydraulic lines whiletuncoupled. Y

It is another object of this invention to provide avalved.;` hydraulic couplingwhich ,hasN a largexOW area-taurina consequent low-pressure dropthrough the-fitting forrelzn.

tively high fluid ow rates.

It is stillanother object ofthisinventionfto proyide .a hydraulic coupling whichmaybe.coupledand uncoupled by hand and which nhas a sealing arrangement effective to prevent leakageduring.high-pressure 'operationw This and other advantages `ofthe presentiI invention :will be apparent from the following description taken in connection with the accompanying drawing.

In the drawing:

Fig. l is a sectional view of the coupling contemplated by this invention showing the coupling elements connected together.

Fig. 2 is a sectional view showing the coupling elements separated and the check valves closed.

Fig. 3 is a sectional view taken along line 3-3 ot' Fig. 2.

Fig. 4 is an enlarged fragmentary view of the seal between adjoining elements of the coupling.

As indicated in the drawings, the coupling consists of two elements, a male portion indicated generally at 1, and a female portion indicated generally at 2. Male portion l consists of an end fitting 3 containing a passage 4, and which is threaded at 5 for attachment to a hydraulic Fice line (not shown), and a valve housing to which iitting 3 is attached by 'means of threads 30; -A chamber 7 formed internally'of the vhousing contains a ball 8 which is urged firmly againstthe"valveseatA 9, when the' coupling is disconnected, by the nspring* 10. Stop ll'servesto guide spring 10 and acts as a stop for ball 8 to limit the extent to which the spring'may be compressed.

The female portion 2 of the coupling consists of an end ttingl?. identical with itting 3, and a valve housing A3' havingl a valve chamber 26 containing a ball 14, spring 15, and stopl," which function in the same manner as thel similar arrangement in the male portion i. A valve rod guide 17 is press-ttedin housing 13jas shown and serves as a guide for valve rod 18 vwhich passes through thel center of the guide and is free to slide axially therethrough. A pin 19 extending through the valve rod acts as a stop andretains 4the rod in the guidev when the coupling elements areseparated. As seenin Fig..3, openings `2ti"and 2l'are provided in -the guide for the free passage of hydraulic fluid therethrough.

The outer end of female member 2 is provided'with a recess 31 to receive'the-terminal portion 3210i the male member 4l in close-fitting relationship. AnV O ring seal 22 `is snugly fitted within the recess 31'and is retained in positionk by annular retainingring 23 which is press fitted into'the housing, vas shown in Fig 4. Coupling nut 24` is carried by thehousing 13 with freedomto rotatev thereon andis retained on the female portion of the coupling, Y

whenit is disconnected, bysnap ring 2511 When the two halves of the coupling are connected together as shownV in Fig.' l, the rod i8 Aextending between the balls 8 and-14 holdsthe valves open against the action of springs f10'a`nd. 15respectively so that the hydraulic fluid may tlow freely through the coupling.

When the lcoupling elements are separatedas shown in Fig-.- 2, the'balls are forced against their respective valve seats by the springs, thus preventing the escape of iiuid from the ,lines whilethe4 coupling remains disconnected.

To vprevent leakage of the'iluid from the coupling while it is operating under, pressure, aA unique `sealing arrangef ment is used. It is obvious that if the sealing' member 22 were subjected to .a high compressive .force each timeV the two.halve`s of the'coupling were connected together, it

would soon deteriorate and its effectiveness would be destroyed. ,On'theother hand, if an ordinary sealing ring or gasketwere used, a highcompressive force would be necessary toefect a satisfactory seal. .In the present device, however, the O rngseal 22'is contained, when the' two halves ofthe coupling are joined, in the recess formed between shoulder 27 "of housing Brand the face 28 of the housing '6. Washer 29 Vwhich is held in place between littingl and housing 6 acts as a stop lfor the coupling nut 24,"limiting theextent to which the'two halves of the coupling may ,beidrawntogether so that O ring 22'is only slightlycompressed whenY the coupling is connected. The pressure 'of thehydraulictluid within the coupling acts against the inner periphery of the 0 ring forcing it tightly into the aforementioned recess and tending to give the O ring an elliptical cross section so that its sides are forced tightly against the shoulder 27 of housing 13 and the face 28 of housing 6, thus eectively sealing the coupling against leakage.

Since the sealing effect of the O ring does not depend on the two halves of the coupling being tightly drawn together, the threads 33 of the coupling nut 24 may have a very long lead so that the coupling may be rapidly and easily connected and disconnected by hand, the resulting hydraulic connection being eicient and leakproof.

When the coupling is operating at high pressures, the O ring will tend to extrude into the joint between the two halves of the coupling and will be damaged when the coupling is separated. To prevent such extrusion, the ring 23, chamfered on its inner periphery, is press fitted into housing 13 so that the chamfered surface provides a smooth bearing surface for the-O ring. Thus eX- trusion of the ring is prevented, the ring 23 at the same time acting as a retaining ring to hold the 0 ring in place when the halves of the coupling are separated.

Because of the simplicity of the construction of the coupling, a large flow area is provided and the flow path through the coupling is essentially unobstructed, so that the pressure drop through the fitting is quite low for any given flow rate.

lt is to be understood that the invention herein described is not confined to the precise details of construction herein set forth, as it is apparent that many changes and variations may be made without departing from the scope of the invention, and no limitation is intended by the phraseology of the foregoing description or the illustrations in the accompanying drawings.

We claim as our invention:

l l. A separable hydraulic coupling for use in conjunctpn with high pressure hydraulic fluid lines comprising, i terfitting male and female members, fastening means for removably fastening said members in interfitting engagement, each of said members having a passage to permit the flow of fluid through said coupling when said members are fastened in intertting engagement, the outer end of said female member providing a recess to receive the terminal portion of said male member in close-fitting relationship, said recess terminating in an inner transverse shoulder, said male member having an end face on said terminal portion, said shoulder and said end face lying in substantially parallel planes and defining a space therebetween when said members are fastened in interfitting engagement, and an O-ring seal member positioned in said recess against said shoulder and having an external diameter substantially equal to the internal diameter of said recess, said seal member normally being greater in thickness than the dimension of said space, and therefore being somewhat compressed between said shoulder and said end face when said male and female members are fastened in intertting engagement, the fluid pressure in said coupling tending to expand the ring against the shoulder and end face whereby leakage between said male and female members is prevented.

2. A separable hydraulic coupling for use in conjunction with high pressure hydraulic fluid lines comprising, interfitting male and female members, fastening means for removably fastening said members in interlitting engagement, each of said members having a passage to permit the flow of fluid through said coupling when said members are fastened .in interfitting engagement, valve means located in the passage of cach of said members, the outer end of said female member providing a recess to receive the terminal portion of said male member in close-fitting relationship, said recess terminating in an inner transverse shoulder, said male member having an end face on said terminal portion, said shoulder and said end face lying in substantially parallel planes and defining a space therebetween when said members are fastened in interfitting engagement, and an O-ring seal member positioned in said recess against said shoulder and having an external diameter substantially equal to the internal diameter of said recess, said seal member normally being greater in thickness than the dimension of said space, and therefore being somewhat compressed between said shoulder and said end face when said male and female members are fastened in intertting engagement, the fluid pressure in said coupling tending to expand the ring against the shoulder and end face whereby leakage between said male and female members is prevented.

3. A separable hydraulic coupling for use in conjunction with high pressure hydraulic fluid lines comprising, interfitting male and female members, fastening means for removably fastening said members in interfitting engagement, each of said members having a passage to permit the ow of fluid through said coupling when said members are fastened in interfitting engagement, valve means located in the passage of each of said members, the outer end of said female member providing a recess t0 receive the terminal portion of said male member in closefitting relationship, said recess terminating in an inner transverse shoulder, said male member having an end face on said terminal portion, said shoulder and said end face lying in substantially parallel planes and defining a space therebetween when said members are fastened in intertting engagement, an O-ring seal member positioned in said recess against said shoulder and having an external diameter substantially equal to the internal diameter of said recess, and a retaining ring in said recess to prevent said seal member from extruding under high pressure, and to keep said seal member from becoming displaced when said male and female members are separated, said seal member normally being greater in thickness than the dimension of said space, and therefore being somewhat compressed between said shoulder and said end face when said male and female members are fastened in interfitting engagement, the fluid pressure in said coupling tending to expand the ring against the shoulder and end face whereby leakage between said male and female members is prevented.

References Cited in the file of this patent UNITED STATES PATENTS 1,137,551 Taby et al. Apr. 27, 1915 1,345,571 Yates July 6, 1920 1,855,264 Thompson Apr. 26, 1932 2,108,714 Hirsch et al. Feb. l5, 1938 2,307,427 Smith et al. Ian. 5, 1943 2,307,828 Eggleston Jan. 12, 1943 2,420,104 Smith May 6, 1947 2,475,206 Smith July 5, 1949 2,614,866 Ulrich Oct. 21, 1952 FOREIGN PATENTS 159,651 Austria Oct. 25, 1949 925,794 France Mar. 31, 1947 

